Simplify Vite configuration instructions

What does this merge request do and why?

This regroups all Vite configuration commands in a single code blocks. This makes it easier to get started by pasting the whole block in one go. This also mirrors the next code block which provides all necessary commands to disable Vite in one go. This should therefore make switching between Vite and Webpack less cumbersome.

How to set up and validate locally

N/A

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• [-] This change is backward compatible. If not, please include steps to communicate to our users.
• [-] Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• [-] Announcement added, if change is notable.
• [-] gdk doctor test added, if needed.
• [-] Add the ~highlight label if this MR should be included in the CHANGELOG.md.